L-carnitine is a chemical produced in the brain, liver and kidneys that helps the body turn fat into energy. Widely available as a supplement, L-carnitine is used by competitive athletes and has also been added to hair loss supplements.
- The in vitro/ex vivo evidence suggests that l-carnitine treatment can elongate hair follicles, prolong the growing stage (anagen), and reduce the levels of proteins that can induce the transitional (catagen) stage of the hair follicle cycle. This evidence, however, hasn’t been replicated.
- The clinical evidence suggests that topical L-carnitine application – over 6 months with twice daily application – can lead to an increase in the total number of hairs, the number of growing (anagen) hairs, and a decrease in the number of resting (telogen) hairs. These are noteworthy results. However, they have not yet been replicated. Further clinical studies are required to confirm these results.
- L-carnitine may improve hair growth outcomes. However, further studies are needed.